The present invention relates generally to a ramp actuating mechanism for a rail vehicle having a ramp and a movable draft arm and coupler arrangement, and more particularly to a ramp actuating mechanism including a spring assisted lifting apparatus for the movable draft arm and coupler arrangement.
The invention is especially suited for a ramp car rail vehicle as described in Applicant""s related patent applications mentioned above. As described in those patent applications, the ramp car rail vehicle can be designed for ease of loading and unloading freight from trains, especially freight in the form of semi-trailers. Conventionally, semi-trailers typically can be loaded on, and unloaded from, rail vehicles only at special railroad terminals equipped with special lifting equipment. However, a ramp car rail vehicle having a ramp and a movable draft arm and coupler arrangement would permit loading and unloading of semi-trailers without such special lifting equipment. This would enable railroads to provide transportation services to shippers far away from such specially equipped terminals. Such ramp car rail vehicles can be equipped with deployable ramps, allowing the semi-trailers to be loaded on, or unloaded from, rail cars at any location accessible to the ramp, such as at grade crossings or in classification yards. As described in Applicant""s aforementioned copending patent applications, such a ramp car rail vehicle can also be configured for use in an integral/semi-integral train employing a segmented roll-on/roll-off freight loading/unloading system. Generally, in such trains multiple rail vehicles can be articulated together, forming segments of an integral train for carrying freight, particularly semi-trailers, wherein each such train segment can have an integrated arrangement composed of different types of rail vehicles.
A ramp raising apparatus for a rail vehicle can include a ramp and a movable draft arm and coupler arrangement having a spring assisted apparatus associated with the movable coupler and draft arm arrangement. The spring assisted apparatus can counterbalance the load of the ramp and movable draft arm and coupler lifting arrangement to reduce raising and lowering impacts of the ramp. The spring assisted mechanism can also reduce the operating air pressure otherwise required to raise and lower the ramp, thereby enabling reduced consumption of pressurized air per cycle of operation.